A substrate for a recording medium suited for thermally assisted recording methods has a disc shape with a center hole and includes a silicon single-crystal supporting member; an SiO2 film formed on the silicon single-crystal supporting member; a main face having a film thickness of the SiO2 film thereon which is less than 10 nm; a substrate inner periphery end face adjacent to the center hole; a substrate inner periphery chamfer portion adjacent to the main face and to the substrate inner periphery end face; a substrate outer periphery end face positioned on the side of the main face opposite the substrate inner periphery end face; and a substrate outer periphery chamfer portion adjacent to the main face and to the substrate outer periphery end face. A magnetic recording medium includes at least the above substrate and a magnetic recording layer formed on the substrate.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A magnetic recording medium that has a disc shape with a center hole, comprising: a silicon single-crystal supporting member having a main face, a substrate inner periphery end face adjacent to the center hole, a substrate inner periphery chamfer portion adjacent to the main face and to the substrate inner periphery end face, a substrate outer periphery end face positioned on a side of the main face opposite the substrate inner periphery end face, and a substrate outer periphery chamfer portion adjacent to the main face and to the substrate outer periphery end face; an SiO 2 film formed on the silicon single-crystal supporting member; and a magnetic recording layer formed on the supporting member for the magnetic recording medium; wherein a thickness of the SiO 2 film on the main face ranges from 2 nm to 8 nm, and a thickness of the SiO 2 film on the substrate inner periphery end face and the substrate inner periphery chamfer portion ranges from 50 nm to 200 nm.
2. The magnetic recording medium according to claim 1 , wherein the SiO 2 film on the substrate outer periphery end face has a film thickness of 10 nm or less.
3. The magnetic recording medium according to claim 2 , wherein at least the SiO 2 film on the substrate inner periphery end face and the substrate inner periphery chamfer portion is formed by thermal oxidation of the silicon single-crystal supporting member.
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December 8, 2008
February 28, 2012
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